Electrical by-pass switch



bq MES, W, A, HElNmCH 2,272,463

ELECTRICAL BY-PASS SWITCH Filed May 13, 1940 3 Sheets-Sheet l A TTOR/EY Fein. 10, 1942. w. A. HEINRICH ELECTRICAL BYJASS SWITCH Filed May 13, 1940 3 Sheets-Sheet 2 .H |.|.|||..|1||. ...l l I I i i l I l I l I I I I I i l l I I..| Lul i i l l l I I i l l I l l I I Ilwl w W11 u r f Feb. 1o, 1942.

W. A. HEINRICH ELECTRICAL BY-PASS SWITCH Filed May 15, 1940 d e f E81 SE1 61 c' ci Cl C2 C C'2 C C C 3 Sheets-Sheet 3 A TroE/vfy Patented Feb. 10, 1942 ELECTRICAL BY-PASS SWITCH Walter Heinrich, Richmond Heights, Mo., as-

signor to James R. Kearney Corporation, St.` Louis, Mo., a corporation of Missouri Application May 13, 1940, Serial No. 334,697

Claims.

cal by-pass switches of the type adapted for use in circuits of power stations, and the like, that include oil circuit breakers for protecting associated equipment, the predominant object of the invention being to provide an improved by-pass switch which includes as a' part thereof movable means for by-passing currenty which movable means is provided with a fusible element that is interposed in the by-pass circuit when current is beingr bypassed by the 'switch so as to afford the protection to the associated equipment under by-pass conditions which is afforded under normal passage of current through the by-pass switch by an associated oil circuit breaker.l

As is quite generally lknown by persons familiar with such matters electrical circuits of power stations, and the like, frequently have interposed therein oil circuit breakers for protecting equipment electrically associated with the circuits. Also heretofore it has been quite common practice to associate with such circuits by-pass circuits, or transfer, buses, as they are commonly called, each of which had electrically associated therewith a spare oil circuit breaker to protect the associated equipment when the current was being by-passed by way of the transfer bus. Oil circuit breakers of the type referred to above are quite expensive and the prime object of the present invention is to provide a by-pass switch which is of such improved construction, and is capable of such use, that no spare oil circuit breaker is required in a by-pass circuit in which one of the improved by-pass switches is interposed. This end is attained by providing a unitary by-pass switch which includes disconnect blades which are movable to closed circuit positions to complete a normal circuit and which includes also movable by-pass means movable to a position, when the disconnect blades are drawn to the open circuit positions, to complete a by-pass circuit. 'I'he movable by-pass means of the improved switch is provided with a relatively inexpensive fusible element that is interposed in the by-pass circuit, when this circuit has been completed through the switch, which affords the protection tothe associated equipment that heretofore was afforded by a relatively expensive spare oil circuit breaker.

Fig. 1 is a front elevation of the improved switch.

Fig. 2 is a side elevation of the switch illusof the movable element of the switch being shown in section.

Fig. 3 is a, fragmentary view partly in front elevation and partly insection of a portion of the movable element of the improved switch.

Fig. 4 is an enlarged cross-section taken on line 4-4ofFig.3. f

Fig. 5 illustrates a wiring diagram of circuits with which the improved switch is employed.

In the drawings, wherein is shown for the purpose of illustration, merely, one embodiment of the invention, A designates the improved switch generally. The switch A includes a suitable supporting member l which, in the embodiment of the invention illustrated inthe drawings, comprises a verticallyl disposed channel bar. Secured by bolts 2 to the member l and extended transversely thereof is a member 3,'and secured by bolts 4 to said member l ata point below the location of the member 3 is a. second transversely extended member 5.

It will be noted by referring to Fig. 1l of the drawings that the transverse members 3 and 5 support a pair of disconnect; switches, a discontrated in Fig. 1, a part of the operating means nect switch which is designated generally b'y the reference character 6 being supported by corresponding end portions ofthe transverse members 3 and 5, and a disconnect switch, designated generally by the reference character 1, being supported by the opposite corresponding end portions of said transverse members 3 and 5.

Referring to the disconnect switch 6 as illustrated in Fig. 2 is will be noted that this switch includes a suitable upper insulator 8 which is disposed horizontally and is Secured to the transverse member 3, and a suitable lower insulator 9 which is likewise disposed horizontally and is secured to the transverse member 5. The upper insulator 8 has secured thereto at its outer end a head l0 which is formed of electrical conducting material, and this head supports an electrical contact Il. The contact Il preferably, though not necessarily, is made up of an assembly of resilient contact elements, the contact being suitably anchored to the head I0 by a plate lla, or otherwise, and having spaced apart forwardly extended contact portions Il'. Likewise the lower insulator 9 of the disconnect switch 6 has secured thereto at its outer end a head l2 which is formed of electrical conducting material, and this head has secured thereto a contact I3 which resembles the contact Il previously described. In other words, the contact I3 associated with the lower insulator 9 is made up of an assembly of resilient contact elements which are suitably anchored to the head I2 by a plate I3a, or other- `wise, said contact elements being shaped to provide the contact I3 with forwardly extended, spaced apart contact -portions I3. Extended forwardly from the head I2 is apair of spaced apart ears Il, and extended downwardly from said head and from'said ears is a terminal I5. 'I'he terminal I5 has mechanically and electrically connected to it, through the instrumentality of a suitable connector I6, a conductor which forms a part of an electrical circuit with which the switch A is associated.

The disconnect switch 6 includes also a switch blade I8 which is provided at its lower end with a member I3 having a portion that receives an end portion of the switch blade and provided with spaced legs I9 which are disposed between the spaced ears I4. The switch blade I8 is con nected to the spaced ears Il -for pivotal movement with respect thereto by a pivot element 20 which is extended through alined openings formed in the spaced ears Il and the spaced legs I3 of the member I8', the extensions I9' of the legs I3 being adapted to contact with abutment means 2l supported by the spaced ears Il so as to limit outward and downward swinging movement of the switch blade about the pivot element 20 (Fig. 2). When the switch blade is moved to the closed switch position it is swung upwardly and inwardly about the pivot element 2|] to a substantially vertical position, as shown to the best advantage in Fig. 2i, where said blade is forced between the spaced, forwardly extended contact portions II and I3' of the contacts II and I3 to make electrical contact therewith.

In order to arrest inward movement of the switch blade Il with respect to the contact Il, the head I associated with the upper insulator I is provided with a forwardly extended stop member 22 with the forward end of which said switch blade is adapted to contact when it has reached the closed switch position. Also the disconnect switch 6 includes means for retaining the switch blade I8 in the closed switch position, said retaining means comprising a bifurcated latch element 23 which is pivoted by means of a pivot element 24 to a lower, forwardly projected extension I0' formed on the head I0. The bifurcated portion of the latch element 23 straddles the switch blade I3 when same is in the closed switch position, and the portions of said latch element at opposite sides of the switch blade are provided with engaging portions 23 which engage pin portions 25 that extend from opposite sides of the switch blade I8 so as to lock the switch blade in the closed switch position. The latch element includes a rigid, upstanding arm 26 and said latch element has associated with it a torsional coil spring 21 which is coiled about the pivot element 2l, as shown in Fig. 2. This coil spring tends to move the forward portion of the latch element in a downward direction, said latch element being provided with an abutment 23 which is adapted to contact with a forward portion of the extension III' to limit such downward movement of the forward portion of the latch element in response to force exerted by the torsional coil spring 21. In order to unlatch the switch blade I3 when it is desired to draw same from the closed switch position, said switch blade has pivotally mounted thereon at 28 a latch operating element 30. The latch operating element 30 includes an eye portion 3| which is adapted to receive a portion of a switch stick, or other suitable tool, for moving the switch blade, and said latch operating element also includes an extension 32 which contacts with the arm 26 of the latch element. Additionally, the latch operating element is provided with abutments 33 which are adapted to contact with the switch blade when said latch operating element is moved to different positions, as will be hereinafter explained.

When the disconnect switch 6 is in the closed switch position, as illustrated in Fig. 2, and it is desired to draw the switch blade I8 out of the closed switch position, a portion of a suitable tool, the finger of a switch stick, for instance. is introduced into the eye portion 3| of the latch operating element and said eye portion is then drawn downwardly to rotate the latch operating element about the pivot 29 with the result that the extension 32 will move the arm 26 of the latch element rearwardly to elevate the bifurcated, forward portion of said latch element. This will release the pin portions 25 from said bifurcated portion of the latch element and will move the lower portions of the abutments 33 into contact with the switch blade I8, and continued downward and outward pull on the eye portion of the latch operating element 30 will swing the switch blade downwardly and outwardly about the pivot 20 and withdraw said switch blade from between the forwardly extended portions of the contacts II and I3. Likewise, to move the switch blade IB from the open switch position to the closed switch position, the eye portion of the latch operating element 30 is engaged by a suitable tool and the switch blade is moved upwardly and inwardly with the upper portions of the abutments 33 in contact with the switch blade. As the switch blade approaches the closed switch position the pin portions 25 will contact with the lcurved faces 23a of lthe latch element and will cam the forward portion of said latch element upwardly, said forward portion of the latch element being moved downwardly by the torsional coil spring 21, to engage the pin portions 25 when the upper portion of the switch blade contacts with the stop member The disconnect switch I is constructed and arranged in accordance with the construction and arrangement of the disconnect switch 6 as hereinbefore described, and therefore it will not be necessary to repeat in detail the description of the switch 1. In other words, the disconnect switch 1 includes upper and lower insulators 8' and 9', a switch blade 3d supported at its lower end for pivotal movement into and out of the closed switch position, contacts 35 and 36 into and out of electrical connection with which the switch blade is movable, and latch means and latch operating means of the type previously described in connection with the description of the disconnect switch 6.

Associated with the disconnect switch 6 is a terminal 31 which extends upwardly and forwardly from the head I0 located at the forward end of the upper insulator 8. This terminal is, of course, formed of electrical conducting material, and at its upper end is provided with a portion 31 having a ilat upper face. Projected transversely from the main body of the terminal is a terminal extension 38 having at its outer end suitable conductor clamping means 39 which is adapted to mechanically and electrically engage a conductor which constitutes a part 0f a circuit with which the switch is electrically associated. Supported by the portion 3l' of the terminal 31 in contact with the flat, upper face thereof is a contact which is made up of an assembly of resilient contact elements, said resilient contact elements being suitably anchored to the terminal portion 31 with portions thereof interposed between the dat face of said terminal portion 31 and a plate 4I. The resilient contact elements which provide the contact 4I) include portions 40a which extend upwardly and outwardly from the portions of said resilient contact elements which are located between the at face of the terminal portion 31' and the plate 4 I, and said resilient contact elements are shaped to provide the contact with inwardly turned, spaced apart portions 40h as shown to the best advantage in Fig. l. Also the plate 4| has extended therefrom a stop member 42, the outer face of which is presented at the lower end of the space between the inturned portions 40h of the contact 40.

The disconnect switch 1 is provided with a terminal 43 which is constructed and arranged just as is the terminal 31 of the disconnect switch 6 previously described herein. That is to say, the terminal 43 of the disconnect switch 1 extends upwardly and outwardly from the `head 8a of the insulator 8 of said disconnect switch and is provided wth an upper terminal portion 43. Also the terminal 43 of the disconnect switch 1 includes a transversely projected terminal extension 44 having at its outer end conductor clamplng means 45 adapted to mechanically and electrically engage a conductor forming a part of a circuit with which the switch is associated. Likewise the terminal 43 of the disconnect switch 1 is provided with a contact 46 made up of an assembly of resilient contact elements shaped to provide base portions which are anchored to the terminal portion 43 and are interposed between a at face of said terminal portion 43' and a plate 41, upwardly and outwardly extended contact portions 46a, and inwardly turned, spaced apart contact portions 4Gb. Additionally the plate 41 has extended therefrom a stop member 48 whose outer end is presented at the lower portion of the space between the inturned contact portions 4Gb of the contact 46.

Supported by -the supporting member I at a point above the upper portions of the disconnect switches 6 and 1 is a movable by-pass member 49, said movable by-pass member being attached by means of a pivot 49 for pivotal movement to a bracket 5D which is secured to the supporting member I. The movable by-pass member 49 in cludes a head 5I through spaced rear portions of which the pivot 49 passes, and secured to said head at its opposite end is an insulator 52. The head 5I is of hollow construction and formed in theopposed side walls thereof are alined openings 53', the ends of said openings which are located adjacent to the pivot 49' being shaped to provide V-shaped seats 54. Extended through the openings 53 of the head 5I is a hollow element 55 of rectangular cross-section which constitutes part of the mechanism for subjecting the movable bypass member 49 to pivotal movement about the pivot 49', said element 55 being seated in the V- shaped seats 54 of the openings 53. 'I'he element 55 is clamped to the head 5I by means of a clamping member 56 which is provided with a V-shaped seat 56 that receives an angular porvthe element 55 between said V-shaped seats 54 of the head and said V-shaped seat 56' of the clamping member 56.

The insulator` 52 has secured thereto at its outer end, by bolts 58, a plate 58 on which is formed a pair of spaced, outstanding ears 59. These ears support a carrier member 6D that is provided with a bottom wall from which is extended a pair of ears 6I. The ears 6I of the carrier member 60 are disposed between the ears 59 of the plate 58 fixed to the insulator 52'as shown in Fig. 3, and a pivot element 62 is extended through alined apertures formed in the ears 59 and the ears 6I for pivotally connecting the carn rier member 60 to the insulator 52. The carrier member 60 is provided with opposed side walls 60a and 60h and is open at its opposite ends, the side walls 60h being provided with a slot 63 which is closed at its inner end and is open at its outer end at the outer edge of said wall 60h. At the location of the slot 63 the wall 60h of the carrier member 60 is relatively thick as indicated at 64 in Fig. 4, and said wall 60h preferably extends a slight distance outwardly beyond the wall 60a with the wall 60h and the wallSIla being curved at their outer end portions as is also indicated in Fig. 4. Wound about the pivot element 62 is a torsional coil spring 65, one end of which contacts with the plate 58 and the opposite end contacting with the outer face of the bottom wall of the carrier member 60. `'Ihe torsional coil spring 65 tends to rotate the carrier member about the pivot member 62 and this rotary movement is limited by a stop 66 which is formed on said carrier member and contacts with the head of one of the bolts 58' which secure the plate 58 to the insulator 52.

The carrier member 60 supports a fuse cartridge 61 which includes a rectangular element 68 through'which an elongated tube structure is extended. The tube structure comprises an outer tube 69 formed by Bakelite or other suitable electrical insulating material of the required strength and durability, and an inner tube 10 formed of horn fiber or other material which is characterized by the ability to give off gas when subjected to the heat of an electric` arc that tends to exl tinguish said arc. The tube structure is retained tion of said element 55 as shown in Fig. 2, said in its proper relation with respect to the rectangular element 68 by pins 1I which are ex tended through apertures formed in said. rectangular element and are seated in grooves 12 formed in opposed portions of the surface of the outer tube 69 (Fig. 4)

The tube structure has fixed thereto at one end thereof a collar. 13 which is mounted partly on the outer tube 69 and partly on the innr tube 10 (Fig. 3), the portion of said collar which is mounted on the inner tube 10 being of reduced external diameter and being externally screwthreaded. Also the tube structure has fixed thereto at a point adjacent to the opposite end thereof a second collar 14. The collars 13 and 14 are formed of electrical conducting material, and said collars have formed thereon and extended therefrom contacts 15 and 16, respectively. Under normal .operating conditions of the switch A the contacts 15 and 16 are electrically connected by a fuse link 11 which is provided at one end with a head 18. The head of the fuse link lcontacts with the end of the inner tube 10 adjacent to which the collar I3 is located, and an internally screwthreaded cap 19, which is screwthreadedly mounted on the reduced externally screwthreaded portion of the collar 13, forcibly engages the head of the fuse 1ink and provides electrical connection between said fuse link head and the collar 13 and contact 15. The fuse link, adjacent to the head 18 thereof is provided with a fusible section, and the portion of the fuse link which extends away from the fusible section in the direction opposite to the location of the head 18 is in the form of a flexible conductor 8|. This conductor is turned about an end of the tube structure and is mechanically and electrically connected to the collar 14 by a wing nut 82 or other suitable means.

, In order to securely fix the fuse cartridge 81 to the carrier member 60 a screwthreaded shank I3 is extended from the rectangular element 68 of said fuse cartridge, said screwthreaded shank I3 being extended through the slot 88 in the wall 88h of the carrier member 68 and has mounted thereon a nut 84. The nut at its inner face supports a washer 85 (Fig. 4) in such manner that the nut may rotate with respect to the washer, and said nut has fixed thereto an eye element I8 which facilitates rotation of the nut about the shank 83. When the fuse cartridge 81 is to be assembled with the carrier member 68, the nut 84 is backed up on the shank 83. The fuse cartridge is then moved downwardly relative to the carrier member until the rectangular element passes into the carrier member, the screwthreaded shank passing downwardly through the slot 83. The nut 84 is then screwed inwardly on the shank 83 until the washer 85 is forced into tight gripping contact with the outer face of the wall 80h of the carrier member 68 to secure the fuse cartridge in place. If desired the outer end of the shank 83 may be riveted over as shown at 83' in Fig. 4 to prevent accidental displacement of the nut 84 from said shank.

The use of the improved switch is illustrated in Fig. 5 wherein T designates transformers and C designates oil circuit breakers which are adapted to protect the transformers from damage resulting from abnormal electrical conditions. The transformers are connected electrically to the conductors a, b, and c in an obvious manner, and the conductors d, e, and f, conduct current from the transformers to the feeder lines g, h, and i. Current passing to the feeder lines g, h, and i flows through switches of the improved construction disclosed herein, the switches associated with said feeder lines g, h, and i, being designated respectively by the reference characters A2, A2 and A3 in Fig. 5. Current flowing to the feeder lines g, h, and i in the normal operation of the switches A1, A2, and A3, where the switch blades I8 and 34 are in closed circuit position, passes from the conductors d, e, and f, by way of the switch blades I8 of the switches and the conductors C1, to the oil circuit breakers, and by way of the conductors C2 and the switch blades 34 of the switches to the feeder lines g, h, and i.

When, however, it is desired to by-pass the current so as to isolate the oil circuit breakers C, the movable by-pass elements 49 are moved downwardly until the contacts and 18 carried by the fuse cartridge 61 move into electrical contact with the contacts 40 and 46 between the inturned portions 40h and 4Gb thereof and are arrested by the stops 42 and 48, and the switch blades I8 and 34 of the switches A1, A2, and A3, are then drawn to the open circuit position in the manner hereinbefore described. When this has been done the current will pass directly from the conductors d, e, and i, to the feeder lines g, h, and z', through the fuse links 8| of the switches A1, A2, and A3. When current is being by-passed around the oil circuit breakers C by way of the fuse links 8| of the switches A1, A2, and A2, the electrical equipment associated with the circuits is protected because of the fact that abnormal electrical conditions on the circuits will rupture the fuse links of the switches before such abnormal conditions may do damage to the equipment. When the main circuit is being re-established the switch blades I8 and 34 are closed befor the movable by-pass elements are opened.

It is to be noted that the element 55, shown in Figs. 1 and 2, is employed only when a plurality of the switches A are gang operated, and when this is so a suitable means (not shown) is employed to move the outer end portions of the movable by-pass elements downwardly to engage the contacts 15 and 16 with the contacts 44 and 48. In the event a single switch A is employed a suitable tool may be used to move the outer portion of the movable by-pass element downwardly to the by-pass position, or this may be done when a plurality of switches are employed. Also it is important to note that the pivotal connection between the carrier member 68 and the plate 58 of the insulator 52, which is provided by the pivot element 62, provides an action resembling a toggle action when the contacts 15 and 16 are being drawn out of engagement with the contacts 40 and 46. In other words the yielding, pivotal movement of the fuse cartridge 61 as the contacts 15 and 16 are being drawn out of engagement with the contacts 40 and 46 tends to break said contacts 15-16 and 48-46 apart with a minimum of effort. The function of the torsional coil spring 65 is to retain the carrier member 60 in its proper position when the contacts 15 and 16 are not in engagement with the contacts 40 and 48 as is shown in Figs. 1 and 2.

I claim:

l. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge supported by said movable bypass element, a pair of spaced contacts supported by said fuse cartridge, a second pair of contacts into and out of electrical contact with which said contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element associated with said fuse cartridge and electrically connecting the contacts thereof, said fusible element normally serving as part of the electrical path provided by said bypass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

2. A by-pass switch comprising a switch structure 4which includes a movable by-pass element, a fuse cartridge supported by said movable bypass element, a pair of spaced contacts supported by said fuse cartridge, means for detachably securing said fuse cartridge to said movable bypass element, a second pair of contacts into and out of electrical contact with which said contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element associated with said fuse cartridge and electrically connecting the contacts thereof, said fusible element normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

3. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure which is supported by said movable bypass element, a pair of spaced contacts supported by said hollow insulating structure, a second pair of contacts into and out of electrical contact with which said contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed within said hollow structure of the fuse cartridge and electrically connecting the contacts supported thereby, said fusible elementI normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

4. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure which is supported by said movable bypass element, a pair of spaced contacts supported by said hollow insulating structure, means for detachably securing said fuse cartridge to said movable by-pass element, a second pair of contacts into and out of electrical contact with which said contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed within said hollow structure of the fuse cartridge and electrically connecting the contacts supported thereby, said fusible element normally serving as part of the electrical path provided by said bypass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

5. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure, a carrier member supported by said bypass element and adapted to receive a portion of said fuse cartridge and provide a support' for said fuse cartridge, a pair of spaced contacts supported by said hollow insulating structure of the fuse cartridge, a second pair of contacts into and out of electrical contact with whichrthe contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed Within said hollow insulating structure of the fuse cartridge and electrically connecting the contacts 'supported thereby, said fusible element normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

6. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure, a carrier member movably supported by said by-pass element and adapted to receive a portion of said fuse cartridge and provide a support for said fuse cartridge, a pair of spaced contacts supported by said hollow insulating structure of the fuse cartridge, a second pair of contacts into and out of electrical contact with which the contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed within said hollow insulating structure of the fuse cartridge and electrically connecting the contacts supported thereby, said fusible element normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

7. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure, a carrier member pivotally supported by said by-pass element and adapted to receive a portion of said fuse cartridge and provide a support for said fuse cartridge, a pair of spaced contacts supported by said hollow insulating structure of the fuse cartridge, a second pair of contacts into and out of electrical contact with which the contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed within said hollow insulating structure of the fuse cartridge and electrically connecting the contacts supported thereby, said fusible element being adapted to be ruptured by passage of abnormal current therethrough.

8. A by-pass switch comprising a switch structure which includes a movable by-pass element,

a fuse cartridge comprising a hollow insulating structure, a carrier member pivotally supported by said by-pass element and adapted to receive a portion of said fuse cartridge and provide a support for said fuse cartridge, spring means associated with said carrier member which tends to maintain said carrier member in a predetermined position relative to said by-pass element, a pair of spaced contacts supported by said hollow insulating structure of the fuse cartridge, a second pair of contacts into and out of electrical contact with which the contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a fusible element a part of which is disposed Within said hollow insulating structure connecting the contacts supported thereby, said fusible element being adapted to be ruptured by passage of abnormal current therethrough.

9. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge comprising a hollow insulating structure, a carrier member pivotally supported by said by-pass element and adapted to receive a portion of said fuse cartridge and provide a support for said fuse cartridge, spring means associated with said carrier member which tends to maintain said carrier member in a. predetermined position relative to said by-pass element, a pair of spaced contacts supported by said hollow insulating structure of the fuse cartridge, means for detachably securing said fuse cartridge to said carrier member, a second pair of contacts into and out of electrical contact with which the contacts of the fuse cartridge are movable to complete and interrupt a by-pass circuit, and a. fusible element a part of which is disposed within said hollow insulating structure of the fuse cartridge and electrically connecting the contacts supported thereby, said fusible element being adapted to be ruptured by passage of abnormal current therethrough.

10. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge supported by said by-pass element, said fuse cartridge comprising a hollow insulating structure, a pair of spaced contacts supported by said hollow structure, a cap electrically associated with one of said contacts, and a fuse link a part of which is disposed within said hollow structure, said fuse link including a head at one end thereof which is electrically contacted by said cap and having a flexible opposite portion which extends out of said hollow structure and is secured mechanically and electrically to the other of said contacts, and a second pair of contacts into and out of electrical contact with which the contacts of said fuse cartridge are movable to complete and interrupt a by-pass circuit.

11. A by-pass switch comprising a switch structure which includes a movable by-pass element, a fuse cartridge supported by said by-pass element, said fuse cartridge comprising a hollow insulating structure, a pair of spaced contacts supported by said hollow structure, a cap electrically associated with one of said contacts, and a fuse link a part o! which is disposed within said hollow structure, said fuse link including a head at one end thereof which is electrically contacted by said cap and having a flexible opposite portion which extends out of said hollow structure and is secured mechanically and electrically to the other of said contacts, means for detachably securing said fuse cartridge to said movable by-pass element, and a second pair of contacts into and out of electrical contact with which the contacts of said fuse cartridge are movable to complete and interrupt a by-pass circuit.

12. A by-pass switch comprising a switch structure which includes a contact, a terminal associated with said contact and adapted to have electrically connected thereto a conductor forming a part oi an electrical circuit, a switch blade movable into and out oi electrical contact with said contact to complete and interrupt the circuit` an auxiliary contact associated electrically with the terminal of said contact, a pivotally supported by-pass element, contact means carried by said movable by-pass element and movable with said by-pass element into and out of electrical contact with said auxiliary contact to complete and interrupt a by-pass circuit, and a fusible element electrically associated with said contact means of said movable by-pass element, said fusible element normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

13. A by-pass switch comprising a switch structure which includes a contact, a terminal associated with said contact and adapted to have electrically connected thereto a conductor forming a part of an electrical circuit, a switch blade movable into and out of electrical contact with said contact to complete and interrupt the circuit, an auxiliary contact associated electrically with the terminal of said contact and supported thereby, a pivotally supported by-pass element, contact means carried by said movable by-pass element and movable with said by-pass element inw and out of electrical contact with said auxiliary contact to complete and interrupt a by-pass circuit, and a fusible element electrically associated with said contact means of said movable by-pass element, said fusible element normally serving as part of the electrical path provided by said bypass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

14. A by-pass switch comprising a switch structure which includes a pair of contacts, terminals associated with said contacts and adapted to have electrically connected thereto conductors forming parts of an electrical circuit, a switch blade associated with each of said contacts and adapted for movement into and out of electrical contact with the associated contact to complete and interrupt the electrical circuit, auxiliary contacts associated electrically with the terminals of said contacts, a pivotally supported by-pass element, a pair of contacts carried by said movable by-pass element and movable with said bypass element into and out of electrical contact with said auxiliary contacts to complete and lnterrupt a by-pass circuit, and a fusible element electrically connecting the pair of contacts carried by said movable by-pass element, said fusible element normally serving as part of the electrical path provided by said by-pass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

15. A by-pass switch comprising a switch structure which includes a pair of contacts, terminals associated with said contacts and adapted to have electrically connected thereto conductors forming parts of an electrical circuit, a switch blade associated with each of said contacts and adapted for movement into and out of electrical contact with the associated contact to complete and interrupt the electrical circuit, auxiliary contacts associated electrically with the terminals oi said contacts and supported thereby, a pivotally supported by-pass element, a pair of contacts carried by said movable by-pass element and movable with said by-pass element into and out oi' electrical contact with said auxiliary contacts to complete and interrupt a by-pass circuit, and a fusible element electrically connecting the pair of contacts carried by said movable by-pass element, said fusible element normally serving as part of the electrical path provided by said bypass circuit and being adapted to be ruptured by passage of abnormal current therethrough to interrupt said by-pass circuit.

WALTER A. HEINRICH. 

